Oxidative stress and antioxidative capacity before and after sleep deprivation

【介绍与方法】本研究旨在评价睡眠剥夺（SD）对应激和疲劳的增加。我们招募了6名没有睡眠问题的健康男大学生加入我们的研究。测量方法为视觉模拟量表（VAS）和以主观嗜睡为指标的卡罗林斯卡睡眠量表（KSS），以及测量简单反应性表现的心理警觉性测试（PVT）。为了评估SD胁迫的生物标志物，我们收集了唾液，通过样品中蛋白质的总浓度校正来评估其酸度和嗜铬粒蛋白A（CgA）的浓度。除了这些测量外，还用FRAS4（H&D srl, Parma, Italy）测量了总血浆氧化剂/抗氧化能力。光盘是一种显色剂，在各种压力作用下产生的氧化剂使其变色。利用光子反应的BAP与抗氧化能力相关。我们在SD前一天的8:00和16:30以及下一个SD日的同一时间进行了四次测量。【结果】VAS和KSS结果显示，SD情况下，受试者的困倦程度明显增加，而PVT在SD情况下的反应性表现水平维持不变。唾液酸度在各处理阶段均呈较高水平，且受SD胁迫无显著变化，而CgA水平则随SD胁迫发生变化。正如之前的研究已经报道的那样，CgA的浓度具有昼夜节律，特别是在我们的受试者不能完全保持清醒，并且在清晨之前进行了短暂的恢复性睡眠。CgA在清晨增加，在傍晚减少。即，与SD前一天一样，在早上前短暂睡眠的受试者在SD日期间的CgA水平在晚上下降。与此同时，在SD日夜间完全不睡觉的受试者中，CgA水平在SD日晚上没有下降。只有两名受试者在SD当天的SD - rom水平明显高于SD前一天。然而，包括前者在内的4名受试者在SD当天晚上的SD - rom水平高于当天早上。4名受试者在SD当天早晨的BAP水平高于SD前一天晚上的BAP水平。在四名受试者中，有三名受试者的BAP水平在SD当天晚上已经下降。【讨论】通过VAS和KSS证实受试者的SD嗜睡，而受试者没有表现出性能受损。正如弗兰岑等人（2008）所指出的那样，主观困倦与生理困倦并不相关，这一观点得到了重申。在本研究中，我们可以表明，在SD期间和之后短暂增加的抗氧化能力可能会抑制SD增加氧化应激的有害作用，并且增加的抗氧化能力可能在一天内消退。这也表明抗氧化能力可能因人而异。CgA可能是一种敏感而有用的SD心理应激生物标志物。少

[Introduction and method] The purpose of this study was to evaluate increase of stress and fatigue by sleep deprivation (SD). Six healthy college male students without sleep problem were recruited into our study. The measurements were Visual analogue scale (VAS) and Karolinska sleep scale (KSS) as an index of subjective sleepiness and Psycho-vigilance test (PVT) which measures simple reactive performance. To evaluate biomarkers of the SD stress, we collected saliva to assess its acidity and concentration of Chromogranin A(CgA) corrected by total concentration of protein in the sample. In addition to those measurements, total plasma oxidant/antioxidant capacity was measured by FRAS4(H&D srl, Parma, Italy). The d-ROM is chromogen which loose color by oxidant produced by any kind of stress. The BAP which utilizes the phenton reaction correlates with the antioxidant capacity. We carried out these measurements four times at 8: 00 and 16: 30 the day before the SD and at that same time on the … More next SD day.[Results] The results of the VAS and KSS indicated significantly increasing sleepiness due to the SD, while reactive performance level by PVT was maintained in the SD situation. The salivary acidity showed high level during all sessions and no significant change by the SD stress, while the level of CgA changed by the SD. As the former studies had already reported, the concentration of CgA had a circadian rhythm, especially in our subjects who were not able to keep awake completely and took a short recovery sleep before early morning. The CgA essentially increases in early morning and decreases in evening. That is, the level of CgA during the SD day in the subjects who took a short sleep before morning decreased in the evening like that on the day before SD. Meanwhile, in the subjects who never slept at all in the night of SD day, the level of CgA did not decrease in evening on the SD day.In only two subjects, the level of d-ROM on the SD day showed substantially higher than that on the day before the SD. However, four subjects including the former had the higher levels of d-ROM in the evening on the day of the SD than that in the morning on that day. In four subjects, the level of BAP was higher in the morning on the day of SD than that in the evening on the day before the SD. In three out of the four subjects, the BAP level had already decreased in the evening on the day of the SD.[Discussion] It was confirmed that subjects' sleepiness by the SD was demonstrated through VAS and KSS, while the subjects did not show impaired performance. It was reaffirmed that subjective sleepiness did not correlate to physical sleepiness as it had been pointed out by Franzen, et. al.(2008).In this study we could indicate the possibility that the antioxidative capacity transiently increased during and after the SD could suppress the harmful effect of increasing oxidative stress by the SD and that the increased antioxidative capacity could subside within a day. It is also suggested that the antioxidative capacity could vary from individual to indivisual. It was also suggested that the CgA could be a sensitive and useful biomarker of psychological stress by SD. Less